Concomitant with wide propagation of various mobile terminals and commercialization of wireless Internet services, demands by consumers related to the mobile terminals are diversified, and various types of additional equipment are attached to the mobile terminals.
Among the various types of additional equipment, a camera module may be a representative device capable of editing and transmitting a still image or a moving picture, as necessary, by photographing the still image or the moving picture, and storing the still image or the moving picture in image data.
In general, the camera module includes a lens unit accommodating at least one lens arranged along an optical axis and an image sensor configured to convert an optical signal of a subject incident from the lens unit into an electrical signal, where the lens unit and the image sensor are mounted in the camera module.
However, only a 2D (two-dimensional) image can be obtained using one lens unit and one image sensor. The 2D image may include damaged information on the light existing in space, and therefore, is limited in its application. That is, the conventional 2D camera module may obtain an integrated value where light components from a single point of an object are gathered at a single point of an image sensor after passing through a lens unit, and therefore, loses information with respect to intensity and direction of individual components of the light.
Henceforth, techniques using a plurality of image sensors are being developed. FIG. 1a illustrates an example of conventional technology, where a lens array (1) is provided. The lens array (1) is formed where a plurality of unit sensors (5) each functioning as an image sensor is arranged on a same plane in plural number, and a plurality of lenses is arranged in a direction traversing an optical axis such that each unit sensor (5) corresponds to each lens.
The camera using plurality of unit sensors (5) causes excessive load on the processor performing image process, and therefore, is useable only for a static image or for a motion picture with low frame rate.
Meanwhile, in order to install the lens array (1) having high light collection rate on the image sensor, a precise six-axis alignment of x, y, z, α, β, and γ is required. In addition, it is practically difficult to manufacture the lens array such that each of the lenses has all the same optical characteristic, or distances from each unit sensor (5) to each lens are all the same. Therefore, the conventional camera module suffers from a problem in that it cannot provide an accurate focal distance for all unit sensors (5).